Communication system, femto-cell base station, authentication device, communication method, and memory medium

ABSTRACT

A communication system that includes at least UE and an HLR that are used in an IMS network further includes: a Femto-cell base station that makes up a predetermined communication area, and a control unit for controlling at least communication between the UE and the HLR. The Femto-cell base station and the control unit are present between the UE and the HLR. The Femto-cell base station includes a transmission unit for transmitting messages received from the UE to the control unit and for transmitting messages received from the control unit to the UE. The control unit converts messages received from the Femto-cell base station to messages that can be recognized by the HLR, and converts messages received from the HLR to messages that can be recognized by the UE.

TECHNICAL FIELD

The present invention relates to technology for implementingcommunication by using a femto-cell base station.

BACKGROUND ART

Recent years has seen advances in the development of communicationsystems that adopt femto-cell base stations that seek to achieve animprovement in quality of communication areas.

A femto-cell base station is a compact wireless base station that coversa limited communication area having a radius in the order of severaltens of meters. A femto-cell base station is installed in a room such asa residence or office to cover an indoor communication area. The use ofa femto-cell base station enables improvement of communication qualityof communication areas that cannot be covered by existing macro-cellbase stations. In addition, communication areas can be covered withoutadding costs for setting up the infrastructure of macro-cell basestations.

Existing 3G networks (communication systems) have been establishedbetween users and communication common carriers. “Existing 3G network”refers to a communication network that carries out communication viaexisting macro-cell base stations. As a result, constructing a newcommunication system by improving the existing 3G network for thepurpose of introducing femto-cell base stations both results in highcosts and places various burdens on the communication common carrier andusers that use the existing 3G network.

As a result, rather than improve an existing 3G network, a newcommunication system must be built that can accept femto-cell basestations.

Literature exists that discloses technology for accessing IMS by way ofWLAN/WWAN that takes into consideration related existing standardspecifications (See Patent Document 1).

Literature exists that discloses certification technology for WLAN.

-   Patent Document 1: JP-A-2006-525762-   Non-Patent Document 1: 3GPP TS 33.234 V8.0.0 (2007-12)

SUMMARY OF THE INVENTION Problem to be Solved by the Invention

Patent Document 1 and Non-Patent Document 1 make no disclosure regardinga technology for introducing a femto-cell base station without improvingan existing 3G network, and further, make no suggestion regarding thisneed.

It is an object of the present invention to solve the above-describedproblem by providing a communication system, a femto-cell base station,an authentication device, a communication method, and a memory mediumthat enable the introduction of a femto-cell base station withoutimproving an existing 3G network (communication system).

Means for Solving the Problem

<Communication System>

The communication system according to the present invention is acommunication system having at least UE (User Equipment) and an HLR(Home Location Register) that are used in an IMS (IP Multimediasubsystem), and that includes:

a femto-cell base station that makes up a predetermined communicationarea; and control means for controlling at least communication betweenthe UE and the HLR; wherein:

the femto-cell base station and control means are present between the UEand the HLR; the femto-cell base station includes transmission controlmeans for both transmitting messages received from the UE to the controlmeans and for transmitting messages received from the control means tothe UE; and

the control means converts messages received from the femto-cell basestation to messages that can be recognized by the HLR, and convertsmessages received from the HLR to messages that can be recognized by theUE.

<Femto-Cell Base Station>

The femtocell base station according to the present invention is afemto-cell base station for accepting messages transmitted from UE,identifying a message that is accepted from the UE as a messagecorresponding to a location registration request of a CS (CircuitSwitching) service, a message corresponding to a location registrationrequest of a PS (Packet Switching) service, or a message correspondingto a PDP Activate, and transmitting to a relay device a messagecorresponding to the message that was identified.

<Authentication Device>

The authentication device according to the present invention is anauthentication device for authenticating UE based on messages that arelay device accepts from a femto-cell base station and subscriberinformation managed by a management device; wherein the authenticationdevice identifies a message accepted from the relay device as a messagecorresponding to a location registration request of PS service, amessage corresponding to a location registration request of a CSservice, or a message corresponding to a PDP Activate, and implementscontrol according to the message that was identified.

<Communication Method>

The communication method according to the present invention is acommunication method implemented by a communication system thatincludes: UE (User Equipment) and an HLR (Home Location Register) thatare used in an IMS (IP Multimedia Subsystem) network, a femto-cell basestation that makes up a predetermined communication area, and controlmeans for controlling at least communication between the UE and the HLR,wherein the femto-cell base station and the control means are presentbetween the UE and the HLR, the communication method including:

transmitting wherein the femto-cell base station transmits messagesaccepted from the UE to the control means;

transmitting wherein the femto-cell base station transmits messagesaccepted from the control means to the UE;

converting wherein the control means converts the messages accepted fromthe femto-cell base station to messages that can be recognized by theHLR; and

converting wherein the control means converts messages accepted from theHLR to messages that can be recognized by the UE.

In addition, the communication method according to the present inventionis a communication method implemented by a femto-cell base station thataccepts messages transmitted from UE, the communication methodincluding:

identifying a message accepted from the UE as message that correspondsto a location registration request of a CS (Circuit Switching) service,a message corresponding to a location registration request of a PS(Packet switching) service, or a message corresponding to PDP Activate,and transmitting to a relay device a message corresponding to themessage that was identified.

Still further, the communication method according to the presentinvention is a communication method carried out by an authenticationdevice that performs authentication of UE based on messages that a relaydevice receives from a femtocell base station and subscriber informationthat is managed in a management device; the communication methodincluding: identifying a message received from the relay device as amessage corresponding to a location registration request of a PSservice, a message corresponding to a location registration request of aCS service, or a message corresponding to PDP Activate, and implementingcontrol according to the message that was identified.

<Memory Medium>

The memory medium according to the present invention is a memory mediumthat can be read by a computer and on which is recorded a communicationprogram that is to be executed by a femto-cell base station thatreceives messages transmitted from UE, the communication program causingthe femto-cell base station to execute processes of identifying amessage received from the UE as a message corresponding to a locationregistration request of a CS (Circuit Switching) service, a messagecorresponding to a location registration request of a PS (PacketSwitching) service, or a message corresponding to PDP Activate, andtransmitting to a relay device a message corresponding to the messagethat was identified.

In addition, the memory medium according to the present invention is amemory medium that can be read by a computer and on which is recorded acommunication program for causing an authentication device to carry outauthentication of UE based on messages received by a relay device from afemto-cell base station and subscriber information that is managed in amanagement device, the communication program causing the authenticationdevice to execute processes of identifying a message received from therelay device as a message corresponding to a location registrationrequest of a PS service, a message corresponding to a locationregistration request of a CS service, or a message corresponding to PDPActivate, and implementing control according to the message that wasidentified.

Effect of the Invention

According to the present invention, a femtocell base station can beintroduced without improving an existing 3G network (communicationsystem).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a block diagram showing a communication system according tothe present exemplary embodiment;

FIG. 1B is a block diagram showing a femtocell base station according tothe present exemplary embodiment;

FIG. 1C is a block diagram showing an authentication device according tothe present exemplary embodiment;

FIG. 2 is an explanatory view of an example of the operation(Authentication OK) of the “CS Location Update (IMSI)/Attach” process;

FIG. 3 is an explanatory view of an example of the operation(Authentication OK) of the “CS Location Update (IMSI)/Attach” process;

FIG. 4 is an explanatory view of an example of the operation(Authentication OK) of the “CS Location Update (IMSI)/Attach” process;

FIG. 5 is an explanatory view of an example of the operation(Authentication NG) of the “CS Location Update (IMSI)/Attach” process;

FIG. 6 is an explanatory view of an example of the processing operationswhen carrying out a Location Update between UE and femto AP;

FIG. 7 is an explanatory view of an example of the processing operationswhen carrying out Location Update between a Femto AP and IMS;

FIG. 8 is an explanatory view of an example of the processing operationsof the “PS Routing Update (IMSI)/Attach” process;

FIG. 9 is an explanatory view of an example of the operations of the “PSRouting Update (IMSI)/Attach” process;

FIG. 10 is an explanatory view of an example of the operations of the“PS Routing Update (IMSI)/Attach” process;

FIG. 11 is an explanatory view of an example of the operations of the“PS Routing Update (IMSI)/Attach” process;

FIG. 12 is an explanatory view of an example of the operations of the PSdispatch time IP sec establishment sequence (Activate PDP ContextRequest) process; and

FIG. 13 is an explanatory view of an example of the operation of the PSdispatch time IP sec establishment sequence (Activate PDP ContextRequest) process.

MODE FOR CARRYING OUT THE INVENTION

(Summary of the Communication System)

An outline of the communication system according to the presentexemplary embodiment is next described while referring to FIGS. 1A-1C.

The communication system according to the exemplary embodiment includes:UE (User Equipment) 3 a-3 d and HLR (Home Location Register) 16 that areused in an IMS (IP Multimedia Subsystem), femtocell base stations (FemtoAP (Femto Access Points)) 21 a and 21 b that make up predeterminedcommunication areas, control unit [PDG 22 (Packet Data Gateway), AAA 23(Authentication Authorization Accounting), HSS 26 (Home SubscriberServer), P-CSCF 24 (Proxy-Call Session Control Function), and S-CSCF 25(Serving-Call Session Control Function)] 29 for controllingcommunication between UE 3 a-3 d and HLR 16 and communication between UE3 a-3 d.

Control unit 29 can be generally called control means.

Femtocell base stations (Femto APs) 21 a and 21 b are of the sameconfiguration. FIG. 1B is a block diagram showing femtocell base station(Femto AP) 21 a.

Femtocell base stations (Femto AP) 21 a and 21 b according to theexemplary embodiment include transmission control unit 211 fortransmitting messages received from any of UEs 3 a to 3 d to controlunit 29 (PDG 22), or transmitting messages received from control unit 29(PDG 22) to any of UEs 3 a to 3 d. Control unit 29 (PDG 22, AAA 23, HSS26, P-CSCF 24, S-CSCF 25) converts messages received from femtocell basestation (Femto AP) 21 a or 21 b to messages that can be recognized byHLR 16, or converts messages received from HLR 16 to messages that canbe recognized by UE 3 a-3 d.

Transmission control unit 211 can typically be referred to astransmission control means. Transmission control unit 211 includesidentification unit 211 a and transmission unit 211 b.

Identification unit 211 a can typically be referred to as identificationmeans. Identification unit 211 a identifies whether a message receivedfrom UE 3 a or 3 b is a message corresponding to a location registrationrequest of a CS (Circuit Switching) service, a message corresponding toa location registration request of a PS (Packet Switching) service, or amessage corresponding to PDP Activate.

Transmission unit 211 b can typically be referred to as transmissionmeans. Transmission unit 211 b transmits a message that corresponds to amessage identified in identification unit 211 a to PDG 22, which is arelay device.

According to the communication system according to the exemplaryembodiment, a femtocell base station can be introduced without improvingan existing 3G network (communication system). The following explanationregards the details of communication systems of the exemplary embodimentwhile referring to the accompanying drawings.

(Example of System Configuration of a Communication System)

The communication system according to the exemplary embodiment is firstdescribed while referring to FIGS. 1A-1C.

The communication system according to the exemplary embodiment includesexisting 3G network 1 and added IMS (IP Multimedia subsystem) network 2.

Existing 3G network 1 is a known existing 3G network. Existing 3Gnetwork 1 includes: UE (User Equipment) 11 a-11 d, Nodes-B 12 a and 12b, RNCs (Radio Network Controllers) 13 a and 13 b, MSC (Mobile ServicesSwitching Center) 14, VLR (Visitor Location Register) 15, and HLR/AuC(Home Location Register/Authentication Center) 16. UE 11 a-11 d, Nodes-B12 a and 12 b, RNCs 13 a and 13 b, MSC 14, VLR 15, and HLR/AuC 16 aredevices for carrying out processes that conform to 3GPP. As a result,explanation is omitted regarding the actual processing operations of UE11 a-11 d, Nodes-B 12 a and 12 b, RNCs 13 a and 13 b, MSC 14, VLR 15,and HLR/AuC 16.

Added IMS network 2 includes: Femto APs (Access Points) 21 a and 21 b,PDG (Packet Data Gateway) 22, AAA (Authentication AuthorizationAccounting) 23, P-CSCF (Proxy-Call Session Control Function) 24, S-CSCF(Serving-Call Session Control Function) 25, HSS (Home Subscriber Server)26, VLR (Visitor Location Register) 27, and RADIUS (RemoteAuthentication Dial-in User Service) 28.

Femto APs 21 a and 21 b are compact wireless base stations that cover asmall communication area having a radius in the order of several tens ofmeters.

PDG 22 is a relay device for relaying messages. PDG 22 receives, forexample, a message received by Femto AP 21 a from UE 3 a. PDG 22transmits messages received from, for example, Femto AP 21 a to AAA 23.

P-CSCF 24 and S-CSCF 25 are included in communication control device 30.P-CSCF 24 and S-CSCF 25 are central nodes in the IMS network. P-CSCF 24and S-CSCF 25 carry out functions such as session control, management,authentication, and routing that use SIP (Session Initiation Protocol).P-CSCF 24 performs control of SIP signals and security control betweenUE 3 a-3 d and P-CSCF 24. S-CSCF 25 performs control of SIP signals andservice control to UE 3 a-3 d.

AAA 23 is an authentication device for carrying out authenticationprocessing between UE 3 a-3 d and the network.

FIG. 1C is a block diagram showing AAA 23. AAA 23 includesidentification unit 23 a and control unit 23 b.

Identification unit 23 a can typically be referred to as identificationmeans. Identification unit 23 a identifies, for example, whether amessage received from PDG is a message corresponding to a locationregistration request of a PS service, a message corresponding to alocation registration request of a CS service, or a messagecorresponding to PDP Activate.

Control unit 23 b can typically be referred to as control means. Controlunit 23 b carries out control according to messages identified inidentification unit 23 a.

HSS 26 is a management device for managing subscriber information of UE3 a-3 d that are used in IMS.

VLR 27 stores the subscriber information of UE 3 a-3 d. HSS 26 acquiresthe subscriber information of UE 3 a-3 d from HLR/AuC 16. HSS 26 storesthe subscriber information of UE 3 a-3 d in VLR 27 and manages thesubscriber information of UE 3 a-3 d. In addition, HSS 26 has thefunction of converting the format of the VLR-formatted subscriber datato an IMS-formatted subscriber data format.

AAA 23 carries out authentication of UE 3 a based on, for example,messages from UE 3 a that PDG 22 received from Femto AP 21 a andsubscriber information managed by HSS 26.

Communication control device 30 controls communication by means of SIPof Femto AP 21 a when authentication of UE 3 a is successful in AAA 23.

RADIUS 28 carries out the authentication process of UE 3 a-3 d.

(Processing Operations of Communication System)

The processing operations of the communication system of the exemplaryembodiment are next described in detail.

(CS Location Update (IMSI)/Attach)

The processing operations for CS (Circuit Switching) Location Update(IMSI)/Attach are next described while referring to FIGS. 2-4.

When UE 3 c, after having registered location in MSC 14 in existing 3Gnetwork 1, moves into LA (Location Area) #3 under the jurisdiction ofFemto AP 21 b in added IMS network 2, UE 3 c begins locationregistration of the CS service (initial location registration). MSC 14in existing 3G network 1 where UE 3 c last registered location is takenas “OLD MSC.” Explanation next regards the processing operations when UE3 c moves to LA#3 that is under the jurisdiction of Femto AP 21 b. Inthe following explanation, it is assumed that IP sec Tunnel (1) has beenestablished between Femto AP 21 b and PDG 22 (Step S1).

UE 3 c transmits a Location Update Request to Femto AP 21 b to carry outupdating (normal location updating) of the LAI (Location AreaInformation) (Step S2).

Femto AP 21 b, upon receiving the Location Update Request, transmits anIDENTITY Request to UE 3 a (Step S3).

Upon receiving the IDENTITY Request, UE 3 a transmits an IDENTITYResponse that includes IMSI.UE to Femto AP 21 b (Step S4). IMSI.UE isinformation for identifying UE 3 a.

Upon receiving the IDENTITY Response, Femto AP 21 b transmits anIKE-SA-INIT Request to PDG 22 (Step S5). IKE-SA-INIT is “Internet KeyExchange-Security Authentication-INITialize”.

PDG 22, having received the IKE-SA-INIT Request, transmits IKE-SA-INITResponse to Femto AP 21 b (Step S6).

Upon receiving the IKE-SA-INIT Response, Femto AP 21 b establishes IKESA between Femto AP 21 b and PDG 22 (Step S7).

Femto AP 21 b next transmits to PDG 22 an IKE-AUTH. Request thatcontains both an APN (Access Point Name) and an NAI (Network AccessIdentifier) (Step S8). IKE-AUTH is Internet Key Exchange-AUTHentication.APN is information for identifying the linking point of the network. NAIis information for identifying access of the network.

The explanation of the operations from Step S1 to Step S8 is heresupplemented. Femto AP 21 b has received a Location Update Request fromUE 3 c, and therefore determines that the message (Location UpdateRequest) received from UE 3 c is a message corresponding to a request toregister the location of a CS service (CS service location registrationrequest). Having been requested to register the location of the CSservice, Femto AP 21 b transmits an IKE-AUTH request that includes a NAIindicating “0CS0<UE_IMSI>/<Femto_IMSI>@realmname” to PDG 22. “0CS0” isinformation indicating the CS service location registration. “<UE_IMSI>”is information for identifying the UE and is IMSI.UE in the IDENTITYResponse that was received in Step S4. “<Femto_IMSI>” is information foridentifying the Femto AP.

Upon receiving the IKE-AUTH request, PDG 22 transmits to AAA 23 aDia-EAP-Request that includes the NAI in the IKE-AUTH Request (Step S9).Dia-EAP is Diameter-Extensible Authentication Protocol.

AAA 23, having received the Dia-EAP-Request, determines based on NAI inthe Dia-EAP-Request whether the Dia-EAP-Request (the message receivedfrom PDG 22) is a CS service location registration request (a messagecorresponding to a request for location registration of the CS service),a PS service location registration request (a message corresponding to arequest for location registration of the PS service), or a PDP Activaterequest (a message corresponding to PDP Activate). When AAA 23determines that the Dia-EAP-Request is a CS service locationregistration request, AAA 23 transmits to HSS 26 the Dia-Wx-MAR thatincludes IMSI.UE indicated in the NAI in the Dia-EAP-Request (Step S10).Dia-Wx-MAR is a Diameter-Wx-Multimedia Authentication Request.

To supplement explanation of the operation of Step S10, AAA 23determines that the Dia-EAP-Request is a CS service locationregistration request because NAI indicates“0CS0<UE_IMSI>/<FemtoIMSI>@realmname.”

Upon receiving Dia-Wx-MAR, HSS 26 transmits MAP-SAI [CS] that includesIMSI.UE in Dia-Wx-MAR to HLR/AuC 16 (Step S11). MAP-SAI is MAP-SendAuthentication Information. [CS] indicates “Circuit Switching.”

HLR/AuC 16, having received MAP-SAI [CS], acquires RAND/AUTN/CK/IK/XREScorresponding to IMSI.UE in MAP-SAI[CS], and transmits to HSS 26 MAP-SAIAck that includes this RAND/AUTN/CK/IK/XRES (Step S12).

RAND/AUTN/CK/IK/XRES is information that conforms to 3GPP. RAND is“Random challenge.” AUTN is “Authentication Token.” CK is “Cipher Key.”IK is “Integrity Key.” XRES is “Expected RESponse.”

In these processing operations, HLR/AuC 16 transmits MAP-SAI Ack thatincludes RAND/AUTN/CK/IK/XRES (EAP-AKA authentication). However, thereare cases in which HLR/AuC 16 transmits MAP-SAI Ack that includesRAND/AUTN/KC/RES (EAP-SIM authentication). HLR/AuC 16 selects eitherEAP-AKA authentication (UMTS authentication) or EAP-SIM authentication(GSM authentication) according to the capacity of the NW with which UE 3c is contracted.

Upon receiving MAP-SAI Ack, HSS 26 transmits to AAA 23 Dia-Wx-MAA thatincludes RAND/AUTN/CK/IK/XRES in MAP-SAI Ack (Step S13). Dia-Wx-MAA is a“Diameter-Wx-Multimedia Authentication Answer.”

Upon receiving Dia-Wx-MAA, AAA 23 transmits to PDG 22 a Dia-EAP-Answerthat includes RAND/AUTN/CK/IK in Dia-Wx-MAA (Step S14).

PDG 22, having received the Dia-EAP-Answer, transmits to Femto AP 21 ban IKE-AUTH Response that contains both an EAP-Request/AKA-Challenge andRAND/AUTN/CK/IK in the Dia-EAP-Answer (Step S15). AKA is “Authenticationand Key Agreement.”

Femto AP 21 b, upon receiving the IKE-AUTH Response, transmits to UE 3 can Authentication Request that includes RAND/AUTN in the IKE-AUTHresponse (Step S16).

Upon receiving the Authentication Request, UE 3 c carries out theauthentication operation based on RAND/AUTN in the AuthenticationRequest (Step S17). The authentication operation is carried out by amethod that conforms with 3GPP.

UE 3 c calculates RES and transmits to Femto AP 21 b an AuthenticationResponse that contains this RES (Step S18). The calculation of RES iscarried out by a method that conforms with 3GPP.

Upon receiving the Authentication Response, Femto AP 21 b transmits toPDG 22 an IKE-AUTH Request that contains both EAP-Response/AKA-Challengeand the RES in the Authentication Response (Step S19).

Upon receiving the IKE-AUTH Request, PDG 22 calculates MAC (MessageAuthentication Code) and transmits to AAA 23 a Dia-EAP-Request thatcontains both the RES and MAC (Step S20). The calculation of MAC iscarried out by a method that conforms with 3GPP.

AAA 23, having received the Dia-EAP-Request, carries out authenticationof the UE (Step S21). The authentication of the UE is carried out by amethod that conforms with 3GPP.

When authentication of the UE is successful, AAA 23 transmits aDia-EAP-Answer that contains EAP-Success to PDG 22 (Step S22).

Upon receiving the Dia-EAP-Answer, PDG 22 transmits a Dia-AA-Requestthat contains APN to AAA 23 (Step S23).

AAA 23, having received the Dia-AA-Request, transmits a Dia-AA-Answerthat contains IMSI.UE to PDG 22 (Step S24).

Upon receiving the Dia-AA-Answer, PDG 22 transmits an IKE-AUTH Responsethat contains EAP-Success to Femto AP 21 b (Step S25).

Femto AP 21 b, upon receiving the IKE-AUTH Response, transmits anIKE-AUTH Request to PDG 22 (Step S26).

Upon receiving the IKE-AUTH Request, PDG 22 transmits an IKE-AUTHResponse to Femto AP 21 b (Step S27).

Upon receiving the IKE-AUTH Response, Femto AP 21 b establishes theIPsec Tunnel (2) between Femto AP 21 b and PDG 22.

Femto AP 21 b next transmits an INFORMATIONAL Request to PDG 22 (StepS29).

Upon receiving the INFORMATIONAL Request, PDG 22 transmits anINFORMATIONAL Response to Femto AP 21 b (Step S30).

PDG 22 further transmits a Dia-ST-Request to AAA 23 (Step S31).

Upon receiving the Dia-ST-Request, AAA 23 transmits a Dia-ST-Answer toPDG 22 (Step S32).

PDG 22, upon receiving the Dia-ST-Answer, releases the IPsec Tunnel (2)that was established in Step S28 (Step S33).

In the exemplary embodiment, the process of UE authentication is carriedout in the state in which the IPsec Tunnel (1) is established betweenFemto AP 21 b and PDG 22 in Step S1. After completion of UEauthentication, there is no need to establish the IPsec Tunnel (2)between Femto AP 21 b and PDG 22 that was established in Step S28. Theprocesses of Step S29-Step S32 are therefore carried out, and the IPsecTunnel (2) that was established in Step S28 is released. As a result,the unnecessary IPsec Tunnel (2) can be released, and efficientutilization of resources can be achieved.

Femto AP 21 b next transmits a SIP-REGISTER that includes IMSI.UE toP-CSCF 24 (Step S34).

Upon receiving the SIP-REGISTER, P-CSCF 24 transmits a Dia-Cx-UAR to HSS26 (Step S35).

Upon receiving the Dia-Cx-UAR, HSS 26 transmits a Dia-Cx-UAA to P-CSCF24 (Step S36).

P-CSCF 24, having received the Dia-Cx-UAA, transmits a SIP-REGISTER thatcontains IMSI.UE to S-CSCF 25 (Step S37).

Upon receiving the SIP-REGISTER, S-CSCF 25 transmits a Dia-Cx-SAR thatcontains IMSI.UE to HSS 26 (Step S38).

HSS 26, having received the Dia-Cx-SAR, transmits the MAP UpdateLocation that includes IMSI.UE to HLR/AuC 16 (Step S39).

Upon receiving the MAP Update Location, HLR/AuC 16 transmits a MAPCancel Location that includes IMSI.UE to OLD MSC (MSC 14) (Step S40).

OLD MSC (MSC 14), having received the MAP Cancel Location, erases theobject subscriber data (Step S41).

OLD MSC (MSC 14) next transmits a MAP Cancel Location Ack to HLR/AuC 16(Step S42).

HLR/AuC 16, upon receiving the MAP Cancel Location Ack, transmitsMAP-Insert Subscriber Data to HSS 26 (Step S43). The MAP-InsertSubscriber Data contains subscriber information of IMSI.UE.

Upon receiving the MAP-Insert Subscriber. Data, HSS 26 producessubscriber data based on the subscriber information of IMSI.UE in theMAP-Insert Subscriber Data (Step S44). HSS 26 registers the subscriberdata in VLR 27 and manages the subscriber data. In addition, HSS 26 hasthe function of converting the format of the VLR-format subscriber datato the format of IMS-format subscriber data.

HSS 26 next transmits a MAP-Insert Subscriber Data Ack to HLR/AuC 16(Step S45).

Upon receiving the MAP-Insert Subscriber Data Ack, HLR/AuC 16 transmitsa MAP-Update Location Ack to HSS 26 (Step S46).

OLD MSC (MSC 14), after erasing object subscriber data in Step S41,deletes the subscriber data from VLR 15 in which the erased subscriberdata is registered (Step S47).

Upon receiving the MAP-Update Location Ack, HSS 26 transmits aDia-Cx-SAA that includes MSISDN to S-CSCF 25 (Step S48).

S-CSCF 25, having received the Dia-Cx-SAA, transmits an SIP-200 OK thatincludes MSISDN to P-CSCF 24 (Step S49).

Upon receiving the SIP-200 OK, P-CSCF 24 transmits the SIP-200 OK thatincludes MSISDN to Femto AP 21 b (Step S50).

P-CSCF 24 further transmits messages to and receives messages fromS-CSCF 25 and carries out a verification process (StepS51/SIP-SUBSCRIBE, SIP-200 OK, SIP-NOTIFY, SIP-200 OK).

Femto AP 21 b, upon receiving the SIP-200 OK, transmits a Security ModeCommand to UE 3 c (Step S52).

Upon receiving the Security Mode Command, UE 3 c carries out concealment(Step S53). The concealment process is carried out by a method thatconforms with 3GPP.

UE 3 c transmits a Security Mode Complete to Femto AP 21 b (Step S54).

Upon receiving the Security Mode Complete, Femto AP 21 b supplementsTMSI (Temporary Mobile Subscriber Identities) (Step S55). Thesupplementation of TMSI is carried out by a method that conforms with3GPP.

Femto AP 21 b transmits messages to and receives messages from S-CSCF 25by way of P-CSCF 24 and carries out verification processes (StepS56/SIP-SUBSCRIBE, SIP-200 OK, SIP-NOTIFIY, SIP-200 OK).

Femto AP 21 b further transmits a Location Update Accept that includesnew TMSI to UE 3 c (Step S57).

UE 3 c, upon receiving the Location Update Accept, transmits a TMSIReallocation Complete to Femto AP 21 b (Step S58).

Thus, in the communication system of the exemplary embodiment, messagesare transmitted and received among UE 3 c, Femto AP 21 b, PDG 22, AAA23, HSS 26, and HLR/AuC 16 in a state in which the IPsec Tunnel (I) isestablished between Femto AP 21 b and PDG 22 (Step S1), authenticationprocesses of UE 3 c are carried out, and when the authentication of UE 3c is successful, the IPsec Tunnel (2) is established between Femto AP 21b and PDG 22 (Steps S2-S28). The IPsec Tunnel (2) between Femto AP 21 band PDG 22 that was established by the authentication process of UE 3 cis then released (Steps S29-S33). Messages are subsequently transmittedand received among Femto AP 21 b, PDG 22, P-CSCF 24, S-CSCF 25, HSS 26,OLD MSC (MSC 14), and HLR/AuC 16; subscriber data of UE 3 a that ismanaged by VLR 15 of OLD MSC (MSC 14) is moved to HSS 26; and thesubscriber data of UE 3 c is registered in VLR 27 of HSS 26 (StepsS34-S44). In this way, the authentication process of UE 3 c can becarried out by way of Femto AP 21 b when registering the location of aCS service and the subscriber data of UE 3 c can be registered in VLR 27of HSS 26.

(Authentication NG (No Subscriber Information))

Processing operations are next described for a case of Authentication NG(No Subscriber Information) with reference to FIG. 5. It is furtherassumed in the process of FIG. 5 that IPsec Tunnel (1) has already beenestablished between Femto AP 21 b and PDG 22 (Step A1).

UE 3 c transmits to Femto AP 21 b a Location Update Request to carry outLAI updating (Normal Location Updating) (Step A2).

Upon receiving the Location Update Request, Femto AP 21 b transmits anIDENTITY Request to UE 3 c (Step A3).

UE 3 c, having received the IDENTITY Request, transmits to Femto AP 21 ban IDENTITY Response that includes IMSI.UE to identify UE 3 c (Step A4).

Upon receiving the IDENTITY Response, Femto AP 21 b transmits anIKE-SA-INIT Request to PDG 22 (Step A5).

PDG 22, having received the IKE-SA-INIT Request, transmits anIKE-SA-INIT Response to Femto AP 21 b (Step A6).

When Femto AP 21 b receives the IKE-SA-INIT response, Femto AP 21 bestablishes IKE SA between Femto AP 21 b and PDG 22 (Step A7).

Femto AP 21 b next transmits to PDG 22 an IKE-AUTH Request that includesan APN (Access Point Name) and a NAI (Network Access Identifier) (StepA8).

The explanation of the processing operations from Step A1 to Step A8 ishere supplemented. Because Femto AP 21 b has received a Location UpdateRequest from UE 3 c, Femto AP 21 b determines that the message (LocationUpdate Request) received from UE 3 c is a message that corresponds to arequest for location registration of a CS service (CS service locationregistration request). When a location registration of a CS service isrequested, Femto AP 21 b transmits an IKE-AUTH request including a NAIthat indicates “1CS0<UE_IMSI>/<Femto_IMSI>@realmname” to PDG 22.“<UE_IMSI>” is information for identifying UE 3 c and is IMSI.UE in theIDENTITY Response received in Step A4. “<Femto_IMSI>” is information foridentifying the Femto AP.

Upon receiving the IKE-AUTH Request, PDG 22 transmits to AAA 23 aDia-EAP-Request that includes the NAI in the IKE-AUTH Request (Step A9).

AAA 23, having received the Dia-EAP-Request, determines based on the NAIin the Dia-EAP-Request whether the Dia-EAP-Request (the message receivedfrom PDG 22) is a CS service location registration request (a messagecorresponding to a request for location registration of a CS service), aPS service location registration request (a message corresponding to arequest for location registration of a PS service), or a PDP Activaterequest (a message corresponding to PDP Activate). Upon determining thatthe Dia-EAP-Request is a CS service location registration request, AAA23 transmits to HSS 26 a Dia-Wx-MAR that contains IMSI.UE indicated bythe NAI in the Dia-EAP-Request (Step A10).

To supplement the explanation of the operation of Step A10, AAA 23determines that the Dia-EAP-Request is a CS service locationregistration request because the NAI indicates“0CS0<UE_IMSI>/<Femto_IMSI>@realmname.”

Upon receiving the Dia-Wx-MAR, HSS 26 transmits a MAP-SAI[CS] to HLR/AuC16 (Step A11).

Upon receiving the MAP-SAI[CS], HLR/AuC 16 transmits a MAP-SAI Ack toHSS 26 (Step A12). In the present operation, the authentication is NG(no subscriber information), and HLR/AuC 16 therefore transmits aMAP-SAI Ack that includes the information “Return error” (Step A12).

The following cases can be considered when HLR/AuC 16 transmits theinformation “Return error” (when authentication is NG):

A case in which subscriber information is not registered (User Unknown);

A case in which data received from HSS 26 is abnormal or in whichnecessary information is missing; and

A case in which HLR/AuC 16 was unable to implement processing correctlydue to some abnormality.

HSS 26, upon receiving the MAP-SAI Ack, transmits to AAA 23 a Dia-Wx-MAAthat includes “User Unknown” because the information “Return error” isincluded in the MAP-SAI Ack (Step A13).

Upon receiving the Dia-Wx-MAA, AAA 23 transmits to PDG 22 aDia-EAP-Answer that includes:“Result:DIA_ERROR_USER_NO_WLAN_SUBSCRIPTION” because “User Unknown” isincluded in the Dia-Wx-MAA (Step A14).

PDG 22, having received the Dia-EAP-Answer, transmits to Femto AP 21 ban IKE-AUTH. Response that includes EAP-Failure because“Result:DIA_ERROR_USER_NO_WLAN_SUBSCRIPTION” is included in theDia-EAP-Answer (Step A15).

Upon receiving the IKE-AUTH Response, Femto AP 21 b transmits a LocationUpdate Accept to UE 3 c (Step A16).

Thus, in the communication system of the exemplary embodiment, messagesare transmitted and received among UE 3 c, Femto AP 21 b, PDG 22, AAA23, HSS 26, and HLR/AuC 16 in a state in which an IPsec Tunnel (1) isestablished between Femto AP 21 b and PDG 22 (Step A1), andauthentication processing of UE is carried out. Upon determining thatauthentication of UE 3 c has failed, Femto AP 21 b transmits a LocationUpdate Accept to UE 3 c (Step A16) and terminates the authenticationprocess of UE 3 c.

(Location Update Request (Periodic) Between UE and Femto AP)

Explanation next regards the implementation of a Location Update betweenUE 3 c and Femto AP 21 b while referring to FIG. 6. The Location Updateis carried out asynchronously.

UE 3 c transmits a Location Update Request to Femto AP 21 b (Step B1).

Upon receiving the Location Update Request, Femto AP 21 b transmits aLocation Update Accept to UE 3 c (Step B2).

In this way, the Location Update is carried out between UE 3 c and FemtoAP 21 b.

(Location Update Request (Periodic) Between Femto AP and IMS)

Explanation next regards the implementation of a Location Update betweenFemto AP 21 b and IMS while referring to FIG. 7. The Location Update iscarried out asynchronously.

Femto AP 21 b transmits a REGISTER that includes IMSI.UE to P-CSCF 24asynchronously (Step C1).

Upon receiving the REGISTER, P-CSCF 24 transmits the REGISTER thatincludes IMSI.UE to S-CSCF 25 (Step C2).

S-CSCF 25, upon receiving the REGISTER, transmits 200 OK to P-CSCF 24(Step C3).

P-CSCF 24, upon receiving 200 OK, transmits 200 OK to Femto AP 21 b(Step C4).

The Location Update is thus carried out between Femto AP 21 b and IMS.

(PS Routing Update (IMSI)/Attach)

Explanation first regards processing operations of a PS (PacketSwitching) Routing Update (IMSI)/Attach while referring to FIGS. 8 and9.

When UE 3 c moves into an RA (Routing Area) that is under thejurisdiction of Femto AP 21 b, UE 3 c begins a PS service locationregistration (Initial Location Registration). The following explanationregards the processing operations when UE 3 c is moving into the RA(Routing Area) that is under the jurisdiction of Femto AP 21 b. In thefollowing explanation, it is assumed that the IPsec Tunnel (1) isalready established between Femto AP 21 b and PDG 22 (Step D1).

UE 3 c transmits to Femto AP 21 b an Attach Request to implementupdating (normal routing updating) of the RAI (Routing Area Information)(Step D2).

Upon receiving the Attach Request, Femto AP 21 b transmits an IDENTITYRequest to UE 3 c (Step D3).

Upon receiving the IDENTITY Request, UE 3 c transmits an IDENTITYResponse that includes IMSI.UE to Femto AP 21 b (Step D4). IMSI.UE isinformation for identifying UE 3 c.

Upon receiving the IDENTITY Response, Femto AP 21 b transmits anIKE-SA-INET Request to PDG 22 (Step D5). IKE SA is then establishedbetween Femto AP 21 b and PDG 22 (Steps D6 and D7)

Femto AP 21 b next transmits to PDG 22 an IKE-AUTH Request that includesboth an APN (Access Point Name) and a NAI (Network Access Identifier)(Step D8).

The explanation of the operations from Step D1 to Step D8 is heresupplemented. Femto AP 21 b has received an Attach Request from UE 3 c,and therefore determines that the message received from UE 3 c (AttachRequest) is a message corresponding to a CS service locationregistration request (request for location registration of a PSservice). When a request is made for PS service location registration,Femto AP 21 b transmits to PDG 22 an IKE-AUTH Request containing a NAIthat indicates: “0PS0<UE_IMSI>/<Femto_IMSI>@realmname.” “0PS0” isinformation signifying that this is a PS service location registration.“<UE_IMSI>” is information for identifying UE 3 c and is IMSI.UE thatwas contained in the IDENTITY Response received in Step D4.“<Femto_IMSI>” is information for identifying the Femto AP.

Upon receiving the IKE-AUTH Request, PDG 22 transmits to AAA 23 aDia-EAP-Request that includes the NAI in the IKE-AUTH Request (Step D9).

Upon receiving the Dia-EAP-Request, AAA 23 determines based on the NAIin the Dia-EAP-Request whether the Dia-EAP-Request (the message receivedfrom PDG 22) is a CS service location registration request (a messagecorresponding to a request for location registration of a CS service), aPS service location registration request (a message corresponding to arequest for location registration of a PS service), or a PDP ActivateRequest (a message corresponding to PDP Activate). AAA 23 determinesthat the Dia-EAP-Request is a PS service location registration requestand then transmits to HSS 26 a Dia-Wx-MAR that includes IMSI.UEindicated by the NAI in the Dia-EAP-Request (Step D10).

The explanation of the operation of Step D10 is here supplemented. AAA23 determines that the Dia-EAP-Request is a PS service locationregistration request because the NAI indicates:“0PS0<UE_IMSI>/<Femto_IMSI>@realmname.”

HSS 26, upon receiving the Dia-Wx-MAR, transmits to HLR/AuC 16 aMAP-SAI[PS] that includes IMSI.UE in the Dia-Wx-MAR (Step D11). [PS]signifies “Packet Switching.”

Upon receiving the MAP-SAI[PS], HLR/AuC 16 acquires RAND/AUTN/CK/IK/XRESthat corresponds to IMSI.UE in the MAP-SAI[PS] and transmits to HSS 26 aMAP-SAI Ack that includes this RAND/AUTN/CK/IK/XRES (Step D12).

The processing of Step D13 to Step D25 is equivalent to the processingof Step S13 to Step S25.

Upon receiving the IKE-AUTH Response, Femto AP 21 b transmits a SecurityMode Command to UE 3 c (Step D26).

UE 3 c, having received the Security Mode Command, transmits a SecurityMode Complete to Femto AP 21 b (Step D27).

Femto AP 21 b, having received the Security Mode Complete, transmits anIKE-AUTH Request to PDG 22 (Step D28).

Upon receiving the IKE-AUTH Request, PDG 22 transmits an IKE-AUTHResponse to Femto AP 21 b (Step D29).

Upon receiving the IKE-AUTH Response, Femto AP 21 b transmits an AttachAccept to UE 3 c (Step D30).

Upon receiving the Attach Accept, UE 3 c transmits an Attach Complete toFemto AP 21 b (Step D31).

Upon receiving the Attach Complete, Femto AP 21 b establishes an IPsecTunnel (3) between Femto AP 21 b and PDG 22 (Step D32).

Processing from Step D33 to Step D37 is equivalent to processing fromStep S29 to Step S33, and the IPsec Tunnel (3) that was established inStep D32 is released (Step D37).

Thus, in the communication system of the exemplary embodiment, messagesare transmitted and received among UE 3 a, Femto AP 21 b, PDG 22, AAA23, HSS 26, and HLR/AuC 16 in a state in which an IPsec Tunnel (1) isestablished between Femto AP 21 b and PDG 22 (Step D1) and theauthentication process of UE 3 c is carried out. When authentication ofUE 3 c is successful, the IPsec Tunnel (3) is established between FemtoAP 21 b and PDG 22 (Steps D2-D32). The IPsec Tunnel (3) that wasestablished between Femto AP 21 b and PDG 22 by the authenticationprocess of UE 3 c is then released (Steps S33-D37). In this way, theauthentication process of UE 3 a can be carried out by way of Femto AP21 b at the time of the location registration of PS service.

(RA Update Request (Macro→Femto AP))

Explanation next regards processing operations when UE 3 c implements anRA Update Request when UE 3 c has moved from existing 3G network 1 onthe macro side to added IMS network 2 that is under the jurisdiction ofFemto AP 21 b while referring to FIGS. 10 and 11. A macro-side PDP isoverwritten when UE 3 c moves from added IMS network 2 to existing 3Gnetwork 1.

UE 3 c transmits to Femto AP 21 b an RA Update Request for implementingupdating (normal routing updating) of RAI (Routing Area Information)(Step E2).

Upon receiving the RA Update Request, Femto AP 21 b transmits to UE 3 can RA Update Reject that includes CV#10 because RAI is macro-sideinformation (Step E3).

Upon receiving the RA Update Reject, UE 3 c transmits an Attach Requestto Femto AP 21 b (Step E4).

The processing from Step E5 to Step E39 is equivalent to processing fromStep D2 to Step D37.

Thus, when RAI is macro-side information, Femto AP 21 b carries out anAttach Request to UE 3 c and carries out the same processes as describedin FIGS. 8 and 9.

(Periodic RA Update Request)

The implementation of a Periodic RA Update Request is next described.

Femto AP 21 b, upon receiving a Periodic RA Update Request from UE 3 c,transmits an RA Update Accept to UE 3 c. The Periodic RA Update Requestis thus carried out.

(IPsec Establishment Sequence upon PS Call Origination)

The processing operations of the IPsec establishment sequence upon PScall origination (Activate PDP Context Request) are next described whilereferring to FIGS. 12 and 13.

UE 3 c transmits an Activate PDP Context Request that includes IMSI.UEto Femto AP 21 b (Step F1).

Upon receiving the Activate PDP Context Request, Femto AP 21 b transmitsan IKE-SA-INIT Request to PDG 22 (Step F2).

Upon receiving the IKE-SA-INIT Request, PDG 22 transmits an IKE-SA-INITResponse to Femto AP 21 b (Step F3).

Femto AP 21 b, having received the IKE-SA-KNIT Response, transmits toPDG 22 an IKE-AUTH Request that includes both an APN (Access Point Name)and a NAI (Network Access Identifier) (Step F4).

Explanation of the operations from Step F1 to Step F4 is heresupplemented. Femto AP 21 b has received an Activate PDP Context Requestfrom UE 3 c and therefore determines that the message received from UE 3c (Activate PDP Context Request) is a message corresponding to a PDPActivate (PDP Activate). When requested for a PDP Activate, Femto AP 21b transmits to PDG 22 an IKE-AUTH Request that contains a NAI thatindicates “0PDP0<UE_IMSI>/<Femto_IMSI>@realmname.” “0PDP0” isinformation indicating a PDP Activate. “<UE_IMSI>” is information foridentifying UE 3 c and is IMSI.UE in the Activate PDP Context Requestthat was received in Step F1. “<Femto_IMSI>” is information foridentifying the Femto AP.

Upon receiving the IKE-AUTH Request, PDG 22 transmits to AAA 23 aDia-EAP-Request that includes both the NAI in the IKE-AUTH Request andEAP-Payload (empty) (Step F5).

Upon receiving the Dia-EAP-Request, AAA 23 determines based on the NAIin the Dia-EAP-Request whether the Dia-EAP-Request (the message receivedfrom PDG 22) is a CS service location registration request (a messagecorresponding to a request to register the location of the CS service),a PS service location registration request (a message corresponding to arequest to register the location of the PS service), or a PDP activaterequest (a message corresponding to PDP Activate). When AAA 23determines that the Dia-EAP-Request is a PDP Activate request, AAA 23transmits to HSS 26 a Dia-Wx-MAR that includes IMSI.UE indicated by theNAI in the Dia-EAP-Request (Step F6).

The explanation of the operation of Step F6 is here supplemented. AAA 23determines that the Dia-EAP-Request is a PDP Activate Request becausethe NAI indicates: “0PDP0<UE_IMSI>/<Femto_IMSI>@realmname.”

Upon receiving the Dia-Wx-MAR, HSS 26 transmits a MAP-SAI[PDP] thatincludes IMSI.UE in the Dia-Wx-MAR to HLR/AuC 16 (Step F7). [PDP] means“PDP Activate.”

Upon receiving the MAP-SAI[PDP], HLR/AuC 16 acquiresRAND/AUTN/CK/IK/XRES that corresponds to IMSI.UE in the MAP-SAI[PDP] andtransmits to HSS 26 a MAP-SAI Ack that includes thisRAND/AUTN/CK/IK/XRES (Step F8).

HSS 26, upon receiving the MAP-SAI Ack, transmits to AAA 23 a Dia-Wx-MAAthat includes RAND/AUTN/CK/IK/XRES in the MAP-SAI Ack (Step F9).

Upon receiving the Dia-Wx-MAA, AAA 23 transmits to PDG 22 aDia-EAP-Answer that includes both Result-Code (multi-round) and anEAP-Request/AKA-Challenge (Step F10).

After receiving the Dia-EAP-Answer, PDG 22 transmits to Femto AP 21 b anIKE-AUTH Response that includes an EAP-Request/AKA-Challenge (Step F11).

Upon receiving the IKE-AUTH Response, Femto AP 21 b transmits anAuthentication Request to UE 3 c (Step F12).

UE 3 c, having received the Authentication Request, transmits anAuthentication Response to Femto AP 21 b (Step F13).

Upon receiving the Authentication Response, Femto AP 21 b transmits toPDG 22 an IKE-AUTH Request that includes both anEAP-Response/AKA-Challenge and a Private Extension (Step F14).

Upon receiving the IKE-AUTH Request, PDG 22 transmits a Dia-EAP-Requestthat includes the EAP-Response/AKA-Challenge to AAA 23 (Step F15).

AAA 23, having received the Dia-EAP-Request, transmits to PDG 22 aDia-EAP-Answer that includes both Result-Code (Success) and anEAP-Request/Success (Step F16).

PDG 22, having received the Dia-EAP-Answer, transmits a Dia-AA-Requestto AAA 23 (Step F17).

Upon receiving the Dia-AA-Request, AAA 23 transmits to PDG 22 aDia-AA-Answer that includes Result-Code (Success) (Step F18).

Upon receiving the Dia-AA-Answer, PDG 22 transmits an Access Request toRADIUS 28 (Step F19).

Upon receiving the Access Request, RADIUS 28 transmits an Access Acceptto PDG 22 (Step F20).

Upon receiving the Access Accept, PDG 22 transmits an Accounting Request(START) to RADIUS 28 (Step F21).

RADIUS 28, having received the Accounting Request (START), transmits anAccounting Response (START) to PDG 22 (Step F22).

Upon receiving the Accounting Response (START), PDG 22 transmits anIKE-AUTH Response that includes EAP-Request/Success to Femto AP 21 b(Step F23).

Upon receiving the IKE-AUTH Response, Femto AP 21 b transmits a SecurityMode Command to UE 3 c (Step F24).

UE 3 c, having received the Security Mode Command, transmits SecurityMode Complete to Femto AP 21 b (Step F25).

Femto AP 21 b, having received the Security Mode Complete, carries out a3G wireless concealment process (Step F26) and transmits an IKE-AUTHRequest to PDG 22 (Step F27). The 3G wireless concealment process iscarried out by a method that conforms with 3GPP.

Upon receiving the IKE-AUTH Request, PDG 22 transmits an IKE-AUTHResponse that includes CF (Remote IP Address) to Femto AP 21 b (StepF28).

CF (Remote IP Address) is an IP address of the connection origin that isreported to the Femto AP when establishing a new IPsec by receivingActivate PDP Context. CF is used in the communication of user data.

Femto AP 21 b, upon receiving the IKE-AUTH Response, transmits anActivate PDP Context Accept to UE 3 c (Step F29), and an IPsec Tunnel(4) is established between Femto AP 21 b and PDG 22 (Step F30).Communication is then carried out between UE 3 c and PDG 22 (Step F31).

Thus, in the communication system of the exemplary embodiment, messagesare transmitted and received among UE 3 c, Femto AP 21 b, PDG 22, AAA23, RADIUS 28, HSS 26 and HLR/AuC 16 and an authentication process of UE3 c is carried out. When the authentication of UE 3 c is successful, notonly is a 3G wireless concealment process carried between UE 3 c andFemto AP 21 b, but an IPsec Tunnel (4) is also established between FemtoAP 21 b and PDP 22 (Steps F1-F30). The process of authenticating UE 3 cis thus carried out by way of Femto AP 21 b during a PDP Activate,thereby enabling both a 3G wireless concealment process to be carriedout between UE 3 c and Femto AP 21 b and an IPsec Tunnel (4) to beestablished between Femto AP 21 b and PDG 22.

The above-described exemplary embodiments are ideal exemplaryembodiments of the present invention, but the scope of the presentinvention is not limited to just the above-described exemplaryembodiments, the present invention being open to various modificationswithin a scope that does not depart from the gist of the presentinvention.

For example, the communication system in the exemplary embodiment neednot depend on the 3GPP Version described in Non-Patent Document 1.

Alternatively, the control operations in each device that make up thecommunication system in the exemplary embodiment described hereinabovecan be realized by using hardware, software, or a construction thatcombines the two.

When a process is executed through the use of software, a program(communication program) that prescribes processing sequences can beinstalled in memory in a computer that is incorporated in dedicatedhardware and these processes then can be executed by execution of theprogram by the computer. Alternatively, a program can be installed in ageneral-purpose computer capable of executing various processes and theprocesses then can be executed by execution of the program by thecomputer.

For example, a program (a communication program) can be recorded inadvance on, as a recording medium, a hard disk or ROM (Read OnlyMemory). Alternatively, a program can be temporarily or permanentlystored (recorded) on a removable recording medium. Such a removablerecording medium can be offered as so-called package software. Examplesthat can be offered as a removable recording medium include: a floppy(registered trademark) disk, a CD-ROM (Compact Disk Read Only Memory),an MO (Magneto-optical) disk, a DVD (Digital Versatile Disc), a MagneticDisk, and semiconductor memory.

The program is installed in the computer from the above-describedremovable recording medium. The program may be wirelessly transferred tothe computer from a download site. The program may be transferred bywire to the computer by way of a network.

In addition, the communication system in the exemplary embodiment can beconstructed to not only execute processes by a time series in accordancewith processing operations described in the above-described exemplaryembodiments, but can be constructed to execute processes in parallel orseparately as necessary according to the processing capability of thedevices that execute processes or according to necessity.

In addition, the communication system in the exemplary embodiment may beconfigured by plurality of devices, or may be configured by aconstruction in which various devices exist within the same case.

(Potential Utility in Industry)

The exemplary embodiment can be applied to services that use Femto-cellbase stations.

Although the invention of the present application was describedhereinabove with reference to each of the exemplary embodiments, theinvention of the present application is not limited by theabove-described exemplary embodiments. The configuration and details ofthe invention of the present application are open to variousmodifications within the scope of the invention that will be readilyunderstood by one skilled in the art.

This application is the National Phase of PCT/JP2009/071249, filed Dec.21, 2009, which claims priority based on Japanese Patent Application2008-333583 for which application was submitted Dec. 26, 2008 andincorporates all of the disclosures of that application.

EXPLANATION OF REFERENCE NUMBERS

-   3, 11 UE (User Equipment)-   12 Node-B-   13 RNC (Radio Network Controller)-   14 MSC (Mobile Services Switching Center)-   15, 27 VLR (Visitor Location Register)-   16 HLR/AuC (Home Location Register/Authentication Center)-   21 Femto AP (Femto Access Point: Femto-cell base station)-   22 PDG (Packet Data Gateway: relay device)-   23 AAA (Authentication Authorization Accounting: authentication    device)-   24 P-CSCF (Proxy-Call Session Control Function: communication    control device)-   25 S-CSCF (Serving-Call Session Control Function: communication    control device)-   26 HSS (Home Subscriber Server: management device)-   28 RADIUS (Remote Authentication Dial-In User Service)

The invention claimed is:
 1. A communication system having at least UE(User Equipment) and an HLR (Home Location Register) that are used in anIMS (IP Multimedia Subsystem) network, and that comprises: a femtocellbase station that makes up a predetermined communication area; and acontrol unit which controls at least communication between said UE andsaid HLR; wherein: said femtocell base station and said control unit arepresent between said UE and said HLR; said femtocell base stationincludes a transmitting unit which transmits messages received from saidUE to said control unit and which transmits messages received from saidcontrol unit to said UE; and said control unit both converts messagesreceived from said femtocell base station to messages that can berecognized by said HLR and converts messages received from said HLR tomessages that can be recognized by said UE; said control unit comprises:a relay device which accepts messages received by said femtocell basestation from said UE; a management device which acquires subscriberinformation of said UE that is stored in said HLR and which managessubscriber information of said UE that was acquired; an authenticationdevice which authenticates said UE based on the messages received bysaid relay device from said femtocell base station and the subscriberinformation that is managed in said management device; and acommunication control device which controls communication by means ofSIP (Session Initiation Protocol) of said femtocell base station whenauthentication of said UE is successful in said authentication device;said femtocell base station identifies a message received from said UEas a message corresponding to a location registration request of a CS(Circuit Switching) service, a message corresponding to a locationregistration request of a PS (Packet Switching) service, or a messagecorresponding to a PDP (Packet Data Protocol) Activate, and transmits tosaid relay device a message corresponding to the message received fromsaid UE that was identified; said relay device transmits to saidauthentication device the message that was received from said femtocellbase station; said authentication device identifies the message receivedfrom said relay device as the message corresponding to the locationregistration request of the PS service, the message corresponding to thelocation registration request of the CS service, or the messagecorresponding to the PDP Activate and implements control according themessage received from said relay device that was identified; saidfemtocell base station: identifies the message that was received fromsaid UE as the message corresponding to the location registrationrequest of the CS service when the message that was received from saidUE is a Location Update Request and transmits to said relay device themessage that contains information corresponding to the messagecorresponding to the location registration request of the CS service;identifies the message that was received from said UE as the messagecorresponding to the location registration request of the PS servicewhen the message that was received from said UE is an Attach Request andtransmits to said relay device the message that contains informationcorresponding to the message corresponding to the location registrationrequest of the PS service; and identifies the message that was receivedfrom said UE as the message corresponding to the PDP Activate when themessage that was received from said UE is an Active PDP Context Requestand transmits to said relay device the message that contains informationcorresponding to the message corresponding to the PDP Activate; and saidauthentication device: based on information contained in the messagereceived from said relay device, identifies the message received fromsaid relay device as the message corresponding to the locationregistration request of the PS service, the message corresponding to thelocation registration request of the CS service, or the messagecorresponding to the PDP Activate.
 2. The communication system accordingto claim 1, wherein: said femtocell base station transmits to said relaydevice the message that contains IMSI (International Mobile SubscriberIdentity) of said UE and IMSI of said femtocell base station; and saidauthentication device carries out authentication of said UE based on theIMSI of said UE that is contained in the message received from saidrelay device that contains the IMSI of said UE and the IMSI of saidfemtocell base station and based on subscriber information that ismanaged in said management device.
 3. The communication system accordingto claim 1, wherein said authentication device: when the messagereceived from said relay device is identified as the messagecorresponding to the location registration request of the PS service,implements control corresponding to the location registration of the PSservice; when the message received from said relay device is identifiedas the message corresponding to the location registration request of theCS service, implements control corresponding to the locationregistration of the CS service; and when the message received from saidrelay device is identified as the message corresponding to the PDPActivate, implements control corresponding to the PDP Activate.
 4. Afemtocell base station which accepts a message transmitted from UE (UserEquipment), said femtocell base station: identifying the messagereceived from said UE as a message corresponding to a locationregistration request of a CS (Circuit Switching) service, a messagecorresponding to a location registration request of a PS (PacketSwitching) service, or a message corresponding to a PDP (Packet DataProtocol) Activate, and transmitting to a relay device the messagecorresponding to the message received from said UE that was identified;and identifies the message that was received from said UE as the messagecorresponding to the location registration request of the CS servicewhen the message that was received from said UE is a Location UpdateRequest, as the message corresponding to the location registrationrequest of the PS service when the message that was received from saidUE is an Attach Request, and as the message corresponding to the PDPActivate when the message received from said UE is an Activate PDPContext Request.
 5. A communication method implemented by acommunication system that includes: UE (User Equipment) and an HLR (HomeLocation Register) that are used in an IMS (IP Multimedia Subsystem)network, a femtocell base station that makes up a predeterminedcommunication area, and a control unit which controls at leastcommunication between said UE and said HLR, wherein said femtocell basestation and said control unit are present between said UE and said HLR;the communication method including: transmitting wherein said femtocellbase station transmits to said control unit messages received from saidUE; transmitting wherein said femtocell base station transmits to saidUE messages received from said control unit; converting wherein saidunit converts messages received from said femtocell base station tomessages that can be recognized by said HLR; and converting wherein saidcontrol unit converts messages received from said HLR to messages thatcan be recognized by said UE; wherein: said control unit comprises: arelay device which accepts messages received by said femtocell basestation from said UE; a management device which acquires subscriberinformation of said UE that is stored in said HLR and which managessubscriber information of said UE that was acquired; an authenticationdevice which authenticates said UE based on the messages received bysaid relay device from said femtocell base station and the subscriberinformation that is managed in said management device; and acommunication control device which controls communication by means ofSIP (Session Initiation Protocol) of said femtocell base station whenauthentication of said UE is successful in said authentication device;said femtocell base station identifies a message received from said UEas a message corresponding to a location registration request of a CS(Circuit Switching) service, a message corresponding to a locationregistration request of a PS (Packet Switching) service, or a messagecorresponding to a PDP (Packet Data Protocol) Activate, and transmits tosaid relay device the message corresponding to the message received fromsaid UE that was identified; said relay device transmits to saidauthentication device the message that was received from said femtocellbase station; said authentication device identifies the message receivedfrom said relay device as the message corresponding to the locationregistration request of the PS service, the message corresponding to thelocation registration request of the CS service, or the messagecorresponding to the PDP Activate and implements control according themessage received from said relay device that was identified; saidfemtocell base station: identifies the message that was received fromsaid UE as the message corresponding to the location registrationrequest of the CS service when the message that was received from saidUE is a Location Update Request and transmits to said relay device themessage that contains information corresponding to the messagecorresponding to the location registration request of the CS service;identifies the message that was received from said UE as the messagecorresponding to the location registration request of the PS servicewhen the message that was received from said UE is an Attach Request andtransmits to said relay device the message that contains informationcorresponding to the message corresponding to the location registrationrequest of the PS service; and identifies the message that was receivedfrom said UE as the message corresponding to the PDP Activate when themessage that was received from said UE is an Active PDP Context Requestand transmits to said relay device the message that contains informationcorresponding to the message corresponding to the PDP Activate; and saidauthentication device: based on information contained in the messagereceived from said relay device, identifies the message received fromsaid relay device as the message corresponding to the locationregistration request of the PS service, the message corresponding to thelocation registration request of the CS service, or the messagecorresponding to the PDP Activate.
 6. A communication method implementedby a femtocell base station that receives messages transmitted from UE(User Equipment), comprising: identifying a message received from saidUE as a message corresponding to a location registration request of a CS(Circuit Switching) service, a message corresponding to a locationregistration request of a PS (Packet Switching) service, or a messagecorresponding to a PDP (Packet Data Protocol) Activate; transmitting toa relay device the message corresponding to the message that wasidentified; and identifying the message that was received from said UEas the message corresponding to the location registration request of theCS service when the message that was received from said UE is a LocationUpdate Request, as the message corresponding to the locationregistration request of the PS service when the message that wasreceived from said UE is an Attach Request, and as the messagecorresponding to the PDP Activate when the message received from said UEis an Activate PDP Context Request.
 7. A memory medium that can be readby a computer and on which is recorded a communication program that isto be executed by a femtocell base station that receives messagestransmitted from UE (User Equipment), said communication program causingsaid femtocell base station to execute processes of: identifying amessage received from said UE as a message corresponding to a locationregistration request of a CS (Circuit Switching) service, a messagecorresponding to a location registration request of a PS (PacketSwitching) service, or a message corresponding to PDP (Packet DataProtocol) Activate, transmitting to a relay device the messagecorresponding to the message that was identified, and identifying themessage that was received from said UE as the message corresponding tothe location registration request of the CS service when the messagethat was received from said UE is a Location Update Request, as themessage corresponding to the location registration request of the PSservice when the message that was received from said UE is an AttachRequest, and as the message corresponding to the PDP Activate when themessage received from said UE is an Activate PDP Context Request.